.. tutorial

Creating mesh and electrodes.
=========================================


This demo is implemented in a single Python file. :download:`tutorial_mesh.ipynb`

This demo illustrates how to:

* Create mesh based in eletrodes
* Use :func:`MyMesh` with :class:`electrodes_position`::

    from module1_mesh import*
    from module2_forward import*
    from module3_inverse import*
    from module4_auxiliar import*
    import matplotlib.pyplot as plt
    %matplotlib inline

**********************
My first mesh!
**********************

::

    "Mesh"
    ele_pos1=electrodes_position(L=4, per_cober=0.8, rotate=0) 
    mesh1=MyMesh(r=1, n=7, n_in=15*2, n_out=3, electrodes_obj=ele_pos1)

    "Rotated Mesh"
    ele_pos2=electrodes_position(L=4, per_cober=0.8, rotate=pi/4*1.2)
    mesh2=MyMesh(r=1, n=7, n_in=15*2, n_out=3, electrodes_obj=ele_pos2)

    "Plot"
    plt.figure(figsize=(8, 8))
    plt.subplot(1,2,1)
    plot(mesh1);
    plt.subplot(1,2,2)
    plot(mesh2);


.. image:: mymesh/rotate.png
   :scale: 75 %

Checking and changing the electrodes position
##################################################

We can use `electrodes_position.position` to check the initial and final of each electrode::
        
    ele_pos1=electrodes_position(L=4, per_cober=0.5, rotate=0) 
    ele_pos1.position
    >>>[[0.0, 0.7853981633974483],
       [1.5707963267948966, 2.356194490192345],
       [3.141592653589793, 3.9269908169872414],
       [4.71238898038469, 5.497787143782138]]

Changing manually electrodes position
****************************************

::

    "Mesh"
    ele_pos1=electrodes_position(L=4, per_cober=0.5, rotate=0)
    mesh1=MyMesh(r=1, n=10, n_in=30, n_out=10, electrodes_obj=ele_pos1)

    "Alternative position"
    ele_pos2=electrodes_position(L=4, per_cober=0.5, rotate=0)
    ele_pos2.position=[
     [0.0, 0.7853981633974483],
     [1.0707963267948966, 1.856194490192345],
     [3.341592653589793, 4.2269908169872414],
     [4.41238898038469, 5.197787143782138]]
    mesh2=MyMesh(r=1, n=10, n_in=30, n_out=10, electrodes_obj=ele_pos2)

    "Plot"
    plt.figure(figsize=(8, 8))
    plt.subplot(1,2,1)
    plot(mesh1);
    plt.subplot(1,2,2)
    plot(mesh2);

.. image:: mymesh/changepos.png
   :scale: 75 %

Fixing excessive cells::
****************************************

To fix the number of vertex in the gaps or in electrodes is just change n_out. If we express n_out as an array, like
n_out=[2,10,2,10] the number of vertex will be different in each selected gap and avoid desnecessary cells.::

    mesh2=MyMesh(r=1, n=10, n_in=30, n_out=[2,10,2,10], electrodes_obj=ele_pos2)

    "Plot"
    plt.figure(figsize=(8, 8))
    plt.subplot(1,2,1)
    plot(mesh1);
    plt.subplot(1,2,2)
    plot(mesh2);

.. image:: mymesh/fixcells.png
   :scale: 75 %

.. warning::
   Watch out for the number of vertices added to the gaps or electrodes.::

    mesh2=MyMesh(r=1, n=10, n_in=30, n_out=[1,1,1,1], electrodes_obj=ele_pos2)

    "Plot"
    plt.figure(figsize=(8, 8))
    plt.subplot(1,2,1)
    plot(mesh1);
    plt.subplot(1,2,2)
    plot(mesh2);

.. image:: mymesh/warning.png
   :scale: 75 %